1. Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University 21 Nanyang Link Singapore 637371 Singapore
2. Institute of Materials Research and Engineering Agency for Science Technology and Research (A*STAR) Singapore 138634 Singapore
3. MajuLab International Joint Research Unit UMI 3654 CNRS Université Côte d'Azur Sorbonne Université, National University of Singapore Nanyang Technological University Singapore Singapore